The urgent need for secure backups

Data loss is no longer a theoretical risk. Ransomware and leaks are turning backups into prime targets, making encryption non‑negotiable. A recent GitProtect report notes that artificial‑intelligence‑driven threats and zero‑trust security models are driving a shift to encrypted backups as a core requirement by 202. Another survey by Spin.AI found that 90 % of organisations worry about the security of cloud backups and 65 % view encryption as the most effective control. When cybercriminals can breach 93 % of company networks and actively seek out unprotected backup repositories, leaving your backup data unencrypted is an invitation for trouble.

In this guide you’ll learn why encrypting your backups matters, how encryption works, and exactly how to apply it on Windows, macOS, Linux, iOS and Android. We’ll also compare popular tools, including why Folder Lock [https://www.newsoftwares.net/folderlock] is a compelling choice for cross‑platform users. Whether you’re protecting family photos or your business’s critical databases, the methods described here will help you build a secure, resilient backup strategy.

Why encryption is essential for backups

It stops attackers turning your backup against you

Backing up your data is only half the story. Attackers increasingly go after backup archives because they know victims will pay more to recover their only copy. Spanning notes that cybercriminals have penetrated 93 % of business networks and often target backups. Encrypting your backup converts the data into unreadable ciphertext that cannot be decrypted without the correct key. This renders stolen backup files useless to attackers and helps you avoid extortion attempts.

It protects privacy and meets compliance requirements

Many laws now require organisations to safeguard customer data at rest. The EU’s GDPR, California’s CCPA and industry standards like PCI‑DSS all emphasise encryption of stored data. Spanning highlights how backup encryption enhances privacy, integrity and authentication while helping organisations comply with these regulations. Bacula Systems adds that encryption reduces the risk of tampering and blackmail and can be an important factor in passing compliance audits.

It shields data during transfer

Backups often travel across networks or to remote storage. Spin.AI stresses that backup data must be encrypted both in transit and at rest, ensuring that intercepted data remains unreadable. Tencent Cloud’s 2025 best‑practice guide likewise lists encryption in transit using strong protocols such as AES‑256 as a key security measure. Without this protection, a simple man‑in‑the‑middle attack can expose sensitive information.

It prepares you for zero‑trust security

Traditional security models assume a trusted internal network. Zero‑trust flips the paradigm by assuming no implicit trust anywhere, even inside your organisation. GitProtect notes that zero‑trust architectures and AI‑driven threat detection are making encrypted backups a baseline requirement. By encrypting backups and isolating keys, you drastically limit the blast radius of a breach.

How encryption works in backups

Encryption uses algorithms to convert plain data into ciphertext that can only be transformed back with a secret key. There are two broad approaches:

• Symmetric encryption: The same key encrypts and decrypts the data. AES (Advanced Encryption Standard) is the industry standard; the Spin.AI report recommends choosing strong key lengths such as 256‑bit and emphasises proper key management. Backups using symmetric encryption are generally faster to process and are ideal for local storage. 
• Asymmetric encryption: A public key encrypts data and a private key decrypts it. Bacula Systems notes that asymmetric encryption can be useful for securely sharing encrypted backups with collaborators. Tools like Folder Lock offer the ability to share encrypted data using this model. 

Encryption at rest vs. in transit

Encryption at rest protects data stored on disk. It ensures that someone who steals your hard drive or cloud account cannot read the backup without the key. Encryption in transit protects data while it’s moving across a network. Both are necessary. Quest’s 2025 security advisory recommends applying strong encryption algorithms for backup data both in transit and at rest, and storing keys separately.

Why AES‑256 is the default choice

Many backup tools use AES‑256 because it provides strong security without significant performance overhead. Tencent Cloud and Spin.AI both recommend AES‑256 for backups. AES‑256 keys are long enough to resist brute‑force attacks for decades, so you can store your data for years without worrying that advances in computing will suddenly make it vulnerable.

Preparing for encryption: key management and password hygiene

Encryption is only as strong as your key management. If you forget the password or lose the key, you won’t be able to decrypt your data. Bacula Systems points out that forgetting a passphrase for a LUKS‑encrypted device can cause permanent data loss because there’s no way to recover it. Similarly, Apple warns that forgetting the FileVault recovery key or login password means you won’t be able to access your Mac. Follow these guidelines:

1. Create strong passwords: Use at least 16 characters with a mix of letters, numbers and symbols. Avoid common words. Consider using a password manager to generate and store them. 
2. Store recovery keys securely: Write down or print recovery keys and store them in a safe place separate from your encrypted device. For online services, store keys in a secure password manager rather than emailing them to yourself. 
3. Don’t reuse passwords: Each encrypted backup should have a unique key. Reusing a password across multiple backups increases the risk of compromise. 
4. Back up encryption metadata: Tools like LUKS store encryption metadata in a header. JumpCloud explains that backing up the LUKS header is critical because if it’s corrupted you will lose access to the entire drive. Always create header backups and keep them offline. 

Encrypting backups on different platforms

Different operating systems have built‑in tools for encryption. Below you’ll find step‑by‑step instructions for the most popular ones. If you prefer a single cross‑platform solution, skip ahead to the section on Folder Lock or open https://folder-lock.com/.

Windows: Device Encryption and BitLocker

Microsoft includes BitLocker Drive Encryption on Windows Pro, Enterprise and Education editions, and Device Encryption on many Windows Home devices. According to Microsoft’s support site, Device Encryption automatically encrypts the operating system drive and fixed drives when you sign in with a Microsoft account. If encryption isn’t already enabled, you can turn it on manually:

1. Sign in with an administrator account. You need administrative privileges to turn on encryption. 
2. Open Settings > Privacy & security > Device encryption (or search for “Device encryption”). 
3. Turn on Device Encryption. Windows will prompt you to back up your recovery key; save it to your Microsoft account, print it or store it in a password manager. 
4. Use BitLocker for removable drives. For external drives or when Device Encryption isn’t available, search for “BitLocker” in Settings, select the drive and click “Turn on BitLocker.” You’ll choose a password or smart‑card PIN and save the recovery key. Once enabled, BitLocker encrypts the entire drive and requires the password to access it. 

Troubleshooting tips

If the Device Encryption toggle is greyed out, make sure you’re signed in with a Microsoft account and that your device supports Modern Standby. For older hardware you may need Windows Pro to use full BitLocker.

macOS: FileVault

Apple’s FileVault encrypts your Mac’s entire startup disk. On Macs with Apple silicon or an Apple T2 security chip the data is already encrypted; turning on FileVault provides an extra layer by requiring authentication before any decryption occurss. To enable FileVault:

1. Open System Settings. Click the Apple menu and choose System Settings. Select Privacy & Security in the sidebar and scroll down to FileVault. 
2. Turn on FileVault. You may be asked for an administrator password. FileVault will begin encryption immediately. 
3. Choose a recovery method. You can unlock your disk using your iCloud account or create a separate recovery key. With the iCloud method, Apple stores an escrow key that can help you reset your password. With the recovery key method, you must securely store the key yourself don’t lose it. 
4. Enable other users. Each user with a separate login must enter their password to unlock the encrypted disk the first time after FileVault is enabled. 

Troubleshooting tips

If your Mac is already encrypted by Apple silicon, FileVault may appear turned off because encryption is handled by the hardware. Turning on FileVault will still protect login data. If you forget both your login password and recovery key, there is no way to access your data.

Linux: LUKS with cryptsetup

Linux Unified Key Setup (LUKS) is the de facto standard for full‑disk encryption on Linux. JumpCloud explains that LUKS provides compatibility across distributions and manages multiple user passwordsj. It stores metadata in a header containing the cipher, key slots and salt. To encrypt a device with LUKS:

1. Install cryptsetup. On Ubuntu run sudo apt update && sudo apt install cryptsetup. 
2. Identify the device (for example, /dev/sdb for an external drive). Ensure it’s unmounted using sudo umount /dev/sdb. 
3. Wipe existing filesystems with sudo wipefs -a /dev/sdb. Warning: This permanently destroys data on the drive. 
4. Format the device with LUKS using sudo cryptsetup luksFormat /dev/sdb. Follow the prompt to type “YES” in uppercase and set a passphrase. 
5. Open the encrypted volume: sudo cryptsetup luksOpen /dev/sdb my-drive. This maps the encrypted device to /dev/mapper/my-drive. 
6. Create a filesystem on the mapped device, e.g., sudo mkfs.ext4 /dev/mapper/my-drive -L my-drive. 
7. Mount the drive: sudo mkdir /mnt/data and sudo mount /dev/mapper/my-drive /mnt/data. 
8. Add backup keys (optional). Use sudo cryptsetup luksAddKey –key-slot 1 /dev/sdb to add another passphrase. 
9. Back up the header. JumpCloud recommends backing up the LUKS header using sudo cryptsetup luksHeaderBackup /dev/sdb ––header-backup-file /root/sdb-header.backup to avoid total data loss. 

Troubleshooting tips

If you forget the passphrase and have no backup keys, your data is unrecoverable. Always back up the header and store copies offline. If the drive fails to mount, ensure you opened it with cryptsetup luksOpen and check that the right device name is used.

iOS: Encrypting local backups

iOS devices automatically encrypt your data when you back up to iCloud, but local backups made through Finder or iTunes are unencrypted by default. To encrypt local backups:

1. Open Finder (macOS Catalina and later) or iTunes (on macOS Mojave and earlier/Windows) and connect your iPhone or iPad. 
2. In the General tab, select Encrypt local backup and set a strong password. Apple warns that if you forget this password there’s no way to recover your backups. 
3. After you enable encryption, previous backups are overwritten and new backups will include sensitive items such as saved passwords and health data. iCloud backups remain encrypted by Apple automatically. 

Troubleshooting tips

If you can’t select Encrypt Local Backup, make sure you’re working on the computer used for sync and that you have updated macOS or iTunes. If you forget the password, you must set up your device as new and will not be able to restore the encrypted backup.

Android: Device encryption

Most modern Android phones automatically encrypt storage. However, you may need to enable encryption on older devices. Cloudwards explains that to complete encryption you need an unrooted phone, at least 80 % battery and a full backup. The steps vary by version:

For Android 4.4 and lower

1. Set up a screen lock: Go to Settings > Security, tap Screen lock and choose a PIN, password or pattern. 
2. Start encryption: Return to Settings > Security and tap Encrypt phone. 
3. Authenticate and wait: Dismiss the warnings, enter your PIN and wait about an hour for encryption to complete. 

For Android 5.0 and higher

1. Go to Settings > Security (sometimes Security & location). If encryption is already enabled it will say so. 
2. If not enabled, tap Encryption & credentials and choose Encrypt phone. 
3. Confirm the warnings and let the process finish; your device may reboot during encryption. 

Troubleshooting tips

If the option is unavailable, your device may already be encrypted or the manufacturer may hide the setting. Some older devices only support SD‑card encryption. Never interrupt the process. If the battery dies mid‑encryption you could lose data permanently.

Choosing a cross‑platform encryption tool

While built‑in solutions are powerful, managing multiple platforms can be cumbersome. A cross‑platform utility lets you protect data consistently across Windows, macOS, Android and even USB drives. Here is a comparison of several common tools:

How to encrypt your backups with Folder Lock

Folder Lock is a commercial application from newsoftwares.net that implements military‑grade AES‑256 encryption without uploading any data to vendor servers. The tool creates Lockers virtual encrypted drives that expand on demand and automatically encrypt files when you copy them in. Here’s how to use it:

1. Install and launch Folder Lock. Download the latest version from the official site (Windows, macOS or Android). Set a master password. The vendor emphasises that this password is never stored locally or on their servers. 
2. Create a new Locker. Click Create Locker and choose whether you want a standard Locker on your computer or a portable Locker for a USB drive. 
3. Set capacity and encryption options. Lockers can be dynamic (expanding as you add files) or fixed size. The encryption engine uses AES‑256 by default. You may also opt for double protection with two passwords. 
4. Add files. Drag and drop folders or files into the open Locker window. Encryption happens on the fly; there’s no waiting for the entire volume to process. When you close the Locker, its files become inaccessible without the master password. 
5. Backup and sync encrypted data. Folder Lock integrates with Dropbox, Google Drive and OneDrive. Clicking Backup will sync the contents of a Locker to your chosen cloud service in encrypted form, so even the cloud provider can’t see your data. 
6. Share securely. Folder Lock allows you to create self‑extracting encrypted files (Lockers) that can be shared with coworkers. Recipients open them with a separate password using asymmetric encryption, ensuring that the master key isn’t shared. 
7. Use portable Lockers. For external drives, choose a portable Locker. This creates an encrypted container that can run without installing Folder Lock, ideal for USB sticks or external HDDs. 
8. Enable stealth features (optional). You can hide Folder Lock itself, password‑protect the application, or use the Shred Files feature to securely delete unencrypted originals. 

Troubleshooting tips

If you forget the master password, there is no backdoor. The vendor doesn’t store your credentials. Make sure to record your password securely. If a Locker won’t open, verify that you’re using the correct version of Folder Lock (portable vs desktop) and that the Locker file hasn’t been renamed or corrupted. Always test your backups by restoring files to ensure integrity.

Additional methods for encrypted backups

If Folder Lock isn’t the right fit, you still have options. Here are some alternative approaches:

• Encrypted archives: Tools like 7‑Zip and PeaZip let you compress folders into .7z or .zip files with AES‑256 encryption. This method is simple and works across platforms, but you must remember to re‑encrypt after any changes. 
• Cloud services with zero‑knowledge encryption: Providers like Sync.com, Tresorit and SpiderOak store data encrypted with keys you control. They offer automatic backup and sharing but require subscriptions. 
• Hardware‑based encryption: Some external drives include built‑in encryption chips and keypad entry. These are easy to use but can be expensive, and if the hardware fails you may lose access. 
• Open‑source disk encryption: VeraCrypt lets you create encrypted volumes or even encrypt your entire system drive. It’s free and audited, but lacks official mobile support. 

Troubleshooting common encryption issues

Forgotten passwords: There’s usually no way to recover encrypted data without the correct key or recovery information. Always maintain multiple copies of recovery keys and store them offline. For FileVault and BitLocker, you can save recovery keys to your Apple or Microsoft account. For LUKS, back up the header file as recommended.

Performance slowdowns: Encryption can add overhead. Most modern CPUs include hardware acceleration for AES, so the impact is minimal. If you notice backups taking much longer, ensure your device supports hardware encryption (Intel AES‑NI, Apple T2/Apple silicon). Using dynamic containers like Folder Lock’s Lockers can also reduce overhead.

Backup corruption: Encrypting doesn’t protect against corruption or hardware failure. Continue to follow the 3‑2‑1 rule three copies of data, on two media, one off‑site. Verify your backups regularly by restoring sample files.

Key storage vulnerabilities: Don’t save passwords in plain text or email them. Use a password manager and multi‑factor authentication. For shared backups, choose tools with asymmetric encryption so collaborators don’t need your master key.

Frequently Asked Questions

1. Why should I encrypt my backups when my original data is already encrypted? Encryption at the source protects the device, but backups are often stored elsewhere or transmitted over networks. Attackers specifically target backup repositories because they may be less protected. Encryption ensures your backups are useless to anyone without the key.
2. What’s the difference between encryption at rest and encryption in transit? Encryption at rest secures data stored on disks. Encryption in transit protects data while it travels across a network. Both are essential to prevent eavesdropping and theft.
3. Which encryption algorithm is best for backups? AES‑256 is widely recommended because it balances strong security with performance. Many tools default to AES‑256, including Folder Lock.
4. Can I encrypt backups stored in the cloud? Yes. Many cloud providers offer client‑side encryption or integrate with tools like Folder Lock. When using public cloud storage, ensure data is encrypted before uploading and that you control the keys.
5. What happens if I forget my encryption password? In most cases the data is unrecoverable. For FileVault and BitLocker you can use recovery keys if you saved them. For LUKS and Folder Lock there is no backdoor.
6. Does encryption slow down my backups? Modern CPUs include hardware acceleration for AES, so the slowdown is minimal. The overhead is usually outweighed by the security benefits. Tools like Folder Lock perform on‑the‑fly encryption that’s barely noticeable during normal use.
7. Are iCloud backups automatically encrypted? Yes. Apple’s iCloud encrypts your backups automatically. Local backups made via Finder or iTunes require enabling the “Encrypt local backup” option.
8. How do I securely share encrypted backups with colleagues? Use a tool that supports asymmetric encryption and shared keys. Folder Lock allows you to create self‑extracting Locker files that can be opened with a separate password, so you don’t have to share your master key.
9. Should I use open‑source encryption or proprietary software? Open‑source tools like VeraCrypt are highly transparent and free, but may lack official support. Proprietary tools like Folder Lock often include extra features (cloud sync, portable containers) and simplified user interfaces. Choose the one that fits your technical comfort and budget.
10. Can I encrypt existing backup archives without re‑backing up? Yes. You can create encrypted archives of existing backups using tools like 7‑Zip or encrypt the disk image with VeraCrypt. Make sure the encrypted container is large enough and test the restoration process afterwards.
11. Is backup encryption required by law? Regulations like GDPR and PCI‑DSS don’t always mandate encryption explicitly, but they require adequate protection of personal data. Encryption is widely regarded as a best practice and may reduce liability in a breach.
12. Are external hardware encryption drives worth it? Hardware‑encrypted drives offer convenience and additional tamper resistance. However, if the controller fails your data may be lost. Software‑based solutions give you more flexibility and redundancy.
13. How often should I rotate encryption keys? For long‑term archives, consider rotating keys every few years or when staff changes occur. Always decrypt and re‑encrypt with the new key. Tools like Folder Lock allow you to change the Locker password without recreating the container.
14. Can I use the same encryption tool on my phone and computer? Yes. Cross‑platform tools like Folder Lock offer apps for Windows, macOS and Android, so you can manage encryption consistently across devices.
15. Does encryption protect against ransomware? Encryption itself doesn’t prevent ransomware infection, but it prevents attackers from reading or selling your data. Maintain up‑to‑date malware protection, implement offline backups and monitor your systems for suspicious activity.

Final thoughts

Encrypting your backups is no longer optional. With attackers actively targeting backup repositories and privacy regulations tightening, unprotected backups represent a serious liability. By understanding the basics of encryption and following the step‑by‑step guides for your platform, you can safeguard your data against theft, tampering and regulatory breaches. Tools like Folder Lock make it easy to apply strong, cross‑platform encryption with cloud‑sync and sharing features, while open‑source alternatives offer flexibility for advanced users. The key is to choose a solution you will actually use one that fits your workflow and ensures that your next backup is both secure and recoverable.